Answer:
m = 8 is the missing variable.
Explanation:
Given:
Let Name the Triangle First as shown in figure.
∴ Δ AOB ~ Δ BOD
AO = 15
CO = 10
BO = m +4
DO = m
To Find:
m = ?
Solution:
If two triangles are similar then their corresponding sides are proportional, and corresponding angles are equal.
∴ Δ AOB ~ Δ BOD
∴
{corresponding sides of similar triangle are in proportion}
∴

Substituting the above given values in it we get
∴

∴ BO = m +4 = 8 + 4 = 12
∴ DO = m = 8